The present invention is applicable to stringed instruments utilizing tremolo bridge assemblies, such as those common to guitars, an example of which is shown in U.S. Pat. No. 2,741,146, to Fender. It is known by those practiced in the art that, although commonly known as tremolo bridges, the effect they create is actually a vibrato effect. Tremolo bridge assemblies are normally located at the end of the strings on the body of the instrument. The strings are typically attached to the bridge assembly and at the other end to tuning pegs which allow for individual string tension adjustment to tune the instrument. Most tremolo bridges pivot, fore-and-aft, at a fulcrum, typically formed by screws, posts, hinge pins or a knife edge. The tension of the strings is counteracted by springs which are attached to an integral part of the tremolo bridge assembly, commonly called the tremolo block. The other ends of the springs are normally attached to the body of the guitar in a manner that allows for adjusting spring tension to accomplish an equilibrium with the tension of the strings when the instrument is in tune. Normally these springs are located inside of the body of the instrument and accessible from the back of the body. This style of tremolo bridge is typically referred to as a “floating” bridge and is most often associated with electric guitars.
A tremolo bridge allows the player to increase or decrease the tension on the strings which changes the pitch the instrument produces, allowing the player to create desired vibrato sound effects. This is normally accomplished by the player manipulating an arm, attached to the bridge, after one or more strings have been strummed. By depressing or raising the arm with enough force to upset the equilibrium between the spring and string tension, the bridge assembly pivots at its fulcrum, which in turn increases or decreases the tension on the attached strings thereby affecting the sound produced.
However, there are problems associated with the common floating tremolo bridge. It is typically time consuming to do the initial setup and tensioning of the tremolo-equipped instrument after new strings are installed, necessitating a procedure of string tensioning and spring adjustment to achieve the required equilibrium. For the inexperienced person, this process can be frustrating. Also, in the event that one of the strings breaks, the remaining strings will go out of tune because the equilibrium is disrupted, rendering the instrument unplayable until the string is replaced and equilibrium is restored. Another problem is that the pitch produced can be affected if the player's hand inadvertently contacts the bridge, which is a common hand resting area, and in doing so disturbs the equilibrium. Yet another problem is experienced if the player intentionally “bends” a string to increase the pitch of a single note, because the pitch of other sound-producing strings will be affected by the disruption to the equilibrium caused by the additional force on the “bent” string.
It is also recognized that the sound producing performance of the instrument is affected by the floating tremolo bridge. The duration that the string or strings produce sound once strummed is referred to in the art as sustain. The dampening effect of the spring biased floating bridge assembly reduces the sustain when compared to a rigid bridge equipped instrument.
Some players of tremolo equipped guitars who do not use the tremolo feature frequently, decide to make the bridge rigid. They eliminate the tremolo feature by locking it down in ways which are not quickly reversible. This is often accomplished by tightening the fulcrum screws along with maximizing the spring tension and adding pieces of wood internally to block the movement of the tremolo block. This does not alter the appearance of the instrument, and by eliminating the tremolo capability, it eliminates the associated problems. However, if the player wishes to restore the tremolo feature, a time-consuming setup procedure will be required to bring it back to function.
Other devices have been proposed to either solve or minimize some of the problems associated with the floating tremolo bridge, but none have addressed all of those listed above. Designs such as Smith U.S. Pat. No. 9,029,671, Cardozo U.S. Pat. No. 9,502,010, Cardoza U.S. Pat. No. 9,697,809, and Wingfield U.S. Pat. No. 5,986,192, provide the ability to lock the tremolo bridge preventing motion in both directions, or unlock the bridge allowing full floating use. However, if applied to existing tremolo equipped instruments, they require the complete replacement or significant modification of the bridge assembly and guitar body, as well as altering the exterior appearance of the instrument.
The lock devices of U.S. Pat. Nos. 7,145,065 and 7,427,703 to Geier, are applicable to existing tremolo equipped instruments. The designs allow the user to lock the tremolo assembly from movement in both directions or to unlock, allowing full motion in both directions. However, if a string breaks while unlocked and in floating operation, the remaining strings go out of tune requiring the replacement of the string and a time-consuming setup procedure before playing can be resumed.
Prior art examples such as McCabe U.S. Pat. No. 9,847,076, McCabe U.S. Pat. No. 9,484,007, Evans U.S. Pat. No. 4,869,145 and Sarricola U.S. Pat. No. 4,823,669, restrict or limit tremolo motion in one direction only. They do not lock the tremolo bi-directionally.
Therefore, there exists a need for a tremolo locking device that will address the above described problems.